@Gary350, I grow my peppers from seeds. Most seeds I have currently are traded seeds that were saved by another gardening friend.
I can’t share the Bill’s Striped seeds because they are “under development” — not even that huge #5 which is not the trait they are looking for. But Bill’s Striped is an offshoot segregate from grow out of
Giant Marconi, which is a popular thick walled sweet (not spicy but actually not candy sweet either) HYBRID variety, and from all I have seen, #5 is showing traits that are similar, so I think you would be able to find plants for this one at garden centers with good variety selection. Bonnie, a popular nursery stock brand, sells this variety so maybe look in stores that carry Bonnie plants.

Giant Marconi Pepper: Smoky Sweet Flavor, Large Fruit
https://bonnieplants.com/product/giant-marconi-pepper/
I don’t know about big box stores, but some independent nurseries would order specific varieties for you as well.
I’m not sure if you are interested in mail order transplants, but if you are, most big seed catalogs like Park Seeds also sell started plants. Park Seeds is in S.C. and have been in mail order seed and garden plant business for a long time. IMHO stick with sources that are geographically close so the package isn’t traveling or stored for many days in transit. In my area there is a huge mail order pepper plant vendor. I have yet to try any from them, but they look good and reliable. There should be ones near you as well.
You might also look for plant sales when your planting time approaches in spring. County or University Ag departments, garden clubs, arboretums, etc. Since you travel and go camping, you might be able to go to some really interesting ones.
If you are interested in heirloom and open pollinated varieties (these are the kind you can save seeds from and plant year after year with same characteristic fruits), I particularly like Southern Exposure Seed Exchange, and if you keep an eye on their event page (or sign up for their e-newsletter) they often participate in gatherings that I’d love to go to but are too far for me.
...look here
Subject: SQWIBS Urban Gardening Adventure 2018
— SQWIB made a comparison between Giant Marconi and Red Marconi from this summer’s garden.